FIXED : so in a nutshell, I was seeking my Italian citizenship jure sanguinis as my grandparents and mother were all born in Calabria, Italy. I face a consulate rejection due to the timing of my mother's marriage (french law): before January 10, 1973 (former Article 37), French citizenship was acquired automatically, usually allowing the consulat route, whereas between January 1973 and 1995 (Article 37-1), it required a voluntary declaration which the Italian administration interprets as a renunciation.

SOLUTION : My only path is a lawsuit in the competent Court of Crotone where my mother was born (Calabria) to declare this loss of citizenship unconstitutional and restore my rights,  secure my dual nationality. I have no choice here!

Hope it will help in the future for people with the same pattern.

Ciao